When Richard Gehring began his thru-hike of the Appalachian Trail in April 2010, he did so with memories of hikes decades earlier, when the AT was relatively unknown. Back in the summer of 1976, he had set out on a southbound thru-hike, starting in Baxter State Park in Maine, hoping to make it to Springer Mountain in Georgia.

In the first 100 miles, between Baxter and Monson, Maine, Gehring recalled, he encountered just seven other hikers.

“Throughout the remainder of Maine, about the only time we saw other hikers were on weekends. We would often comment whenever we saw a new hiker that it must be the weekend,” Gehring said.

While Gehring didn’t finish his thru-hike as intended in 1976, he came back for several years, completing different sections of the AT until he had hiked the equivalent of the entire length of the trail in May of 1981.

In 2010, Gehring decided to give a thru-hike another go. He was struck by how much use of the trail had increased since his first trek 30 years earlier.

“Down south, the shelters were almost always full, the privies overflowing, and many of the hostels were full,” he said. “If you ask a hiker today, the only reality they may know is the trail they are experiencing today. So, to them, the trail may not seem overcrowded.”

For decades, the Appalachian Trail has offered escape, capturing the imagination of generations of Americans looking to spend more time in the outdoors, building a relationship with nature or challenging their endurance. But as more and more people have looked to the promise of the AT for freedom, some have developed concerns about the trail’s sustainability.

Studying hikers’ impact on the AT

Those concerns have captured the attention of hikers and trail authorities alike. In 2014, a recreational ecologist from Virginia Tech launched the most comprehensive study of the AT ever conducted. Jeff Marion’s multi-year project aims to analyze sections of the trail for signs of erosion using Geographic Information Systems technology.

An avid hiker himself, Marion believes his study will serve to help manage the trail and preserve an “unfettered wilderness experience” into the future. But based on his findings, Marion fears that the need for increased regulation is inevitable.

“The AT community is very, very concerned about not overregulating the Appalachian Trail … We are bound and determined to preserve that in any way we can,” Marion said. “But professional recreational ecology suggests that if the use keeps continuing to grow, at some point we are going to have to cross that bridge – to limit use and employ regulations in some cases.”

Equipped with state-of-the-art GPS systems, Marion led a team through the northern third of the trail last year. He sampled five-kilometer sections of the AT from Connecticut to Maine. The team plans to conduct research on the southern third this year and the middle third next year. Marion and his team intend to publish their results in 2018.

Marion shared some of his results from the northern third.

“The trail alignment in the Northeast is not terribly sustainable,” he said. “There’s a lot of problems where the grade of the trail is often very steep and the alignment angle of the trail is close to the fall line.”

This steep design, he said, exacerbates erosion from both water runoff and soil displacement as hikers walk.

Mounting problems at Mount Katahdin

This problem, and others caused by hikers, have become prominent recently in Baxter State Park, the AT’s northern terminus. The park’s director, Jensen Bissell, said the presence of too many hikers has, at times, negatively impacted the trail.

“In Baxter, we have a pretty good record of enforcement of those who violate park rules. And the reason we try to mitigate or enforce punitive actions against that is that, in general, all those things have a negative effect on visitor experience, and, to some degree, the resources of the park itself,” Bissell said.

He said one of the worst problems he and his staff face is hikers congregating in large groups to summit the trail’s final mountain, Mount Katahdin.

“When large groups of AT hikers bottle up waiting to complete their hike … we find we might have 25 or 30 AT hikers hiking together, walking outside the trail corridor in a very sensitive habitat, like the top of Katahdin,” he said.

Leave No Trace, a nonprofit organization that educates people about their recreational impact on nature, wrote on its website that hiking off trail can trample “vegetation or communities of organisms” beyond recovery. The resulting lack of plant life then leads to soil erosion, damage to surrounding habitats and, ultimately, less attractive trails. This damage is particularly bad in a sensitive alpine habitat like Mount Katahdin.

As a result, Baxter State Park enforces a long list of rules. Bissell explained why in a 2014 letter to the Appalachian Trail Conservancy, whose volunteers and clubs protect and maintain the trail.

Bissell cited various problems in the park: Besides traveling in large groups, hikers were camping in undesignated areas, hiking with pets, drinking and using recreational drugs and littering.

Kevin Seagraves, information coordinator for Leave No Trace, said these behaviors are harmful to the environment. Camping in undesignated areas is like hiking off trail. “That affects the environment in an aesthetic way. It also breaks up the environment and disturbs creatures that already live there,” Seagraves said.

Should the AT limit the number of hikers?

Bissell said the AT cannot accommodate an unlimited number of hikers.

“We very clearly see the trends in growth here, and going from 300 hikers a year to 1,700 – over 2,000 if we count all the hikers – is a big change,” he said. “And we don’t see any evidence in the line of that curve for that growth to stop. And we don’t see anything in the Appalachian Trail Conservancy’s policy to suggest it should. So that’s the conundrum we’re trying to work out.”

In his letter, Bissell said the conservancy’s model is “based on unlimited growth in use.”

By comparison, he said, Baxter State Park has a “discrete cap model.” This means the park puts a limit on the number of campsites and parking spaces available each day in order to restrict the number of visitors. Bissell said the limited growth model has a positive impact on the environment in the park and on visitors’ experiences.

Formally, the Appalachian Trail has no such limit on the number of users. Neither does Baxter State Park when it comes to the number of hikers who may enter on foot.

Bissell said he and other park authorities are working on ways to create and enforce such a limit.

“We proposed a more formal registration process that the AT hiker [must do], and this applies only to northbound thru-hikers, flip-floppers and section hikers, not southbounders,” Bissell said. (Flip-floppers are hikers who start in the middle of the Appalachian Trail, at Harpers Ferry, W.Va.; hike north to Mount Katahdin; then return to Harpers Ferry and hike south to Springer Mountain. It’s a way to avoid crowds.)

“Eventually this could be a tool where we begin to apply an annual limit to the number of AT folks that will come into the park. That would provide a management framework that is more similar and consistent with what all other visitors ... have been going through.”

Alternatives to limiting hikers

While high-use problems exist elsewhere along the trail, other people have their own opinions about the best solutions.

Jay Dement is the information and education director for the Georgia Appalachian Trail Conservancy, which helps maintain another highly used section of trail. He said the “three crucial elements to preventing environmental degradation are education, education and education.”

Dement knows about sustainability education: He serves as Georgia’s Leave No Trace state advocate and helped organize a recent Leave No Trace Hotspot cleanup event in southern Georgia.

Dement said compiling and predicting the number of hikers is hard because hikers can get on or off the trail in so many places and they don’t need a permit.

However, as of April 5, he said, 1,300 thru-hikers and 800 section hikers had registered this year in trail logs at Amicalola Falls State Park in Georgia, the closest park to the trail’s southern terminus.

Dement predicted that at least 3,000 hikers total would begin thru-hikes in Georgia this year.

“In such great numbers, it’s hard to not have a major impact,” Dement said. “We see them all over the trail, being ill-prepared both with what they’re carrying and their habits: not knowing privies aren’t for trash, not realizing that camping over there in that bed of flowers is not a good idea … Somebody has got to tell them what to do.”

Marion agreed that inexperienced hikers who begin the trail in Georgia bring their own set of problems.

“You would think that people who are preparing to hike the entire Appalachian Trail are relatively seasoned, experienced backpackers. In fact, that’s not the case,” Marion said. “A lot of these folks are really complete novices, and so the attrition rate is remarkably high. A lot of them never get out of Georgia – or at least North Carolina, Tennessee and the Smoky Mountains.”

“When I was a Boy Scout, our Boy Scout leaders told us to take a can of beans and stick it in a fire, eat the beans and then you smash the can and bury it,” he said. “This is what I was taught, which was totally wrong.”

That is why it’s crucial to provide proper information to hikers, Dement said.

“Maybe I’m naive, but I believe most people want to do things the right way. If they’re given the chance, if they’re told how the whole thing works, then they can figure out how to conduct themselves on a hike. Then, that is going to dramatically mitigate the problem,” Dement said.

He believes limiting hikers’ access to trails is not the answer. Instead, he recommends “alternative thru-hikes” like flip-flops and section hikes, as Gehring did from 1976-1981.

Dement also wants the Appalachian Trail Conservancy to recognize alternative trails that parallel the AT – like the Benton MacKaye Trail, which runs from Springer Mountain to Great Smoky Mountains National Park – as part of a thru-hike. This would spread out the hikers.

“You can’t eliminate a problem by eliminating the access,” Dement said. “If people understood what the problems were, and shown that there were other places where they could go to recreate, then we could all live a whole lot better.”

Marion agrees with Dement that education is essential for reducing harmful impact on the trail. Marion has written a book “Leave No Trace in the Outdoors.” And in his role on the Appalachian Trail Conservancy’s board of sustainability, he has helped proliferate Leave No Trace information and signage along the AT.

Marion also advocates for voluntary programs that have been instituted for particularly high-use areas such as Springer Mountain in Georgia and the Presidential Range in the White Mountains of New Hampshire.

By participating in a voluntary registration system, introduced by the Appalachian Trail Conservancy this year, prospective thru-hikers can share their start dates with other thru-hikers and plan their itinerary to avoid overcrowding on the Appalachian Trail.

‘Before limits, try everything else first’

Hawk Metheny, the conservancy’s regional director for New England, agreed that following Leave No Trace ethics and avoiding popular hiking areas during peak times does much to limit impact. But he fears that ultimately, limits on hiker numbers may be needed.

He said the Appalachian Trail Conservancy’s recent efforts to formalize data collection on hikers may yield a better understanding of the trail’s limit.

“We’ve hired a visitor use program manager to apply more study and science to the popular sections to better determine the limits of acceptable change and the carrying capacity of the trail comprehensively,” Metheny said. “We want to get better science to work with land management groups to inform on whether we need to introduce quotas, permits or changes otherwise in regulation.”

It will be up to land management groups – not the Appalachian Trail Conservancy – to decide whether to implement such regulations, Metheny emphasized.

Despite planning for the worst, Metheny seemed optimistic about efforts to deal with overuse problems by other means: “Before we implement limits like these, we’re going to try everything else first. But we haven’t crossed that threshold yet.”

Marion agreed. While he believes growing use of the AT might prompt more regulation, Marion is optimistic that his study will help the Appalachian Trail Conservancy, its trail clubs and the National Park Service improve conditions along the trail.

“It’s just that at some point with the sheer number of people, even if they are practicing Leave No Trace, we’re still going to end up with problems,” Marion said. “The voluntary efforts and Leave No Trace is helping, but ultimately it won’t be enough.”

To Marion, a quota or permit system seems inevitable.

In the Western U.S., high-demand parks use a lottery system to award hiking permit and limit the number of hikers. Marion says that could be a solution to overcrowding on certain segments of the Appalachian Trail.

Gehring isn’t sure how such a limit could be enforced on a route as long as the 2,190-mile Appalachian Trail. But he believes that the explosion in hikers has negatively impacted the trail.

“People who have not experienced the AT until recently do not know how the trail experience has changed,” he said. “If all they know is that crowds are the norm, that may not dissuade them from hiking. Others who have experienced a more solitary trail experience may choose a different trail or a different approach to the AT.”